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

Annotations already declare readOnly, idempotent and non-destructive, so the safety profile is covered. The description adds genuine behavioral context beyond that: it warns there is no aggregate score or ranking and that period, scale and missing values must be interpreted per source. That is meaningful for correctly reading the result.

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?

Three short, front-loaded sentences with no filler. The scope constraint leads, followed by the two interpretation caveats, so the most decision-relevant information comes first.

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 values need not be explained, and annotations cover the safety profile. Still, for a comparison tool with an undocumented `dimensions` enum and no routing to the single-street sibling, the description leaves gaps an agent must resolve elsewhere.

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 0%, so the description must carry parameter meaning. It documents the street_ids constraint ('2–5 distinct IDs') matching minItems/maxItems, but says nothing about the `dimensions` parameter or its enum values (walkability.nwi, food.snap_retailers, transport.ev_stations), leaving half the inputs opaque.

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 operation and scope: 'Side-by-side contextual measurements for 2–5 distinct IDs.' This clearly conveys a multi-street comparison, distinguishing it from the single-street sibling get_street_context by implication. It stops short of naming that sibling, so differentiation is inferred rather than explicit.

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 statement 'No overall score, ranking or recommendation' sets output expectations, and 'Interpret each source period, scale and missing value separately' offers interpretation guidance. However, it never states when to choose this over get_street_context or when comparison is inappropriate, leaving usage to inference.

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