Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and openWorldHint=true, so the agent knows this is a safe read operation that may interact with external systems. The description adds useful behavioral context: it accepts 2–5 origins, returns them ranked fastest to slowest with best available route details (duration, distance, transit lines, traffic-aware driving time), and handles individual lookup failures gracefully by surfacing errors in-line rather than aborting the whole comparison. This goes beyond the annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the main purpose, followed by example questions and behavioral notes. While the example section is useful, it could be slightly more concise. However, it remains focused and avoids unnecessary repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

The description is complete for an agent to call the tool correctly: it explains the input range (2–5 origins), output format (ranked list with route details), error handling, and use cases. An output schema exists, so return values need not be detailed, but the description still provides enough behavioral context to be self-sufficient. Minor gap: no explicit mention of rate limits or authentication needs, which are unlikely for a read-only comparison tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so all parameters (mode, origins, avoid_tolls, destination, departure_time) are already documented in the schema. The description adds no additional parameter syntax or format details beyond what the schema provides, such as address formatting or departure time format. When schema coverage is high, a 3 is the baseline.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb (compares) and resource (commute times), and precisely scopes the operation: multiple candidate origins to a single shared destination using real-time Google Maps data. It distinguishes itself from the sibling get_transit_commute by handling multiple origins and ranking them, rather than a point-to-point lookup.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description gives clear context through example questions, showing exactly when to use it (ranking apartments by commute, comparing neighborhoods). It also clarifies what the tool does NOT do: 'Compare driving vs. transit isn't needed — just rank these addresses by commute time.' However, it doesn't explicitly name the sibling get_transit_commute or state when to use that alternative.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint and openWorldHint, so the safety profile is covered, but the description adds real value by scoping the returned data (notably the hard cap of 'up to 5 user reviews' and full weekly hours rather than a summary). It does not mention rate limits, quota costs, or whether fields like hours can be missing for some places, leaving a small gap.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the payload, then the hard prerequisite, then illustrative intents. Every sentence earns its place and the bulleted examples aid selection without bloat.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a single-required-param read tool with full schema coverage and an existing output schema, the description supplies everything needed: the prerequisite chain, the returned content, and when to reach for it. No missing decision-relevant information.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and the single parameter is already documented with its source and format ('ChIJ…') in the schema itself. The description's instruction to source the ID from a prior search_places call largely restates the schema, adding only mild emphasis; baseline 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (returns) and resource (details about a specific place), then enumerates the concrete payload: phone, website, full weekly opening hours, editorial summary, and up to 5 reviews. This clearly separates it from search_places, which returns result lists rather than one place's detail.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Explicitly states the prerequisite ('Always requires a place ID obtained from a prior search_places call') and frames the tool as a follow-up to search_places, with three concrete user-intent examples that select this tool over its siblings.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations provided, the description carries the full burden and does well: it discloses real-time vs predicted traffic behavior, the default mode, multi-leg support, and a concrete return shape (up to 3 alternatives with duration, lines, transfers, walking time). It omits auth/permission requirements and rate limits, which is a minor gap rather than a critical one.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with purpose, then usage, then capabilities and return values — a logical order. It is slightly padded ('commute, travel time, or exact travel times' is near-redundant), but every line still contributes information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so return-value detail is not strictly required, yet the description adds useful shape information anyway. Together with the fully documented schema, an agent has enough to invoke the tool correctly; only sibling disambiguation and auth expectations are unaddressed.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the schema already documents mode defaults, avoid_tolls scope, intermediates, and departure_time semantics — the description mostly restates these. The A→B→C example adds a little clarity but no new semantics beyond what the schema supplies, so the baseline of 3 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource ('returns commute routes between two addresses') and names the underlying data source and supported modes. It is clear what the tool does, but it never distinguishes itself from the sibling compare_commutes, which an agent could plausibly reach for on the same query.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit trigger conditions ('user asks about commute, travel time, or exact travel times between two addresses'), which is solid when-to-use guidance. It offers no when-not-to-use and does not name compare_commutes as the alternative for multi-address comparison, leaving that routing decision to inference.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The annotations already declare readOnlyHint=true and openWorldHint=true, so safety is covered. The description adds useful behavioral context beyond that: real-time Google Maps data, a maximum of 20 returned results, the result fields provided, and the handoff condition to get_place_details. It does not cover rate limits or auth requirements, so it is strong but not exhaustive.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with the core action, then immediately gives concrete trigger examples, then summarizes output and the routing alternative. Every section is useful and there is no filler.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

An output schema exists, so the description does not need to explain return values in full, yet it still summarizes the result shape and the detail-retrieval follow-up. For a read-only discovery tool with complete parameter documentation, nothing essential is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, so the baseline is 3. The description provides example query strings and notes the return count, but it does not materially extend the meaning of near, type, open_now, or max_results beyond what the schema already documents.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource ('Searches for places') and enumerates the kinds of places covered. It clearly distinguishes this discovery tool from the sibling get_place_details by explaining that details require passing a result id to that sibling.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit example user queries that should trigger this tool, says when to use it, and points to get_place_details for deeper information about a specific result. The when-to-use and alternative routing are both explicit.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.