search_agencies

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

With no annotations, the description carries the full burden. It partially does so by disclosing the returned fields (portable location, grade, score, expiry, readiness), which is valuable given there is no output schema. But it says nothing about read-only nature, ordering, pagination beyond the schema's limit default, or auth requirements.

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?

Two sentences, zero filler, and the search scope is front-loaded before the return-value sentence. Every clause (filter dimensions, returned fields) carries distinct 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?

Given no output schema, the description usefully enumerates the return payload, which is the main completeness risk. It falls slightly short on pagination/ordering and filter-combination behavior for a six-parameter search tool, but nothing critical for a correct call 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 schema already documents all six parameters including the 'prefer subdivision' hint. The description groups and names the same dimensions but adds no syntax, format, or interaction semantics (e.g., AND vs OR across filters) beyond what the schema provides; 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 (Search) and resource (tracked transit agencies), then enumerates the searchable dimensions (name, id, ISO country, subdivision, legacy state, grade). This clearly separates it from stats/aggregation siblings such as national_stats, get_rollup, and get_scorecard, which return computed values rather than agency records.

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?

Usage is implied by the enumeration of filter dimensions, so an agent can infer this is the lookup tool for individual agencies. However, there is no explicit when-to-use versus alternatives (e.g., coverage_for or get_scorecard for aggregate views) and no guidance on combining filters or when results are exhaustive.

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