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

Annotations cover the safety profile (readOnly, idempotent, non-destructive, closed-world), and the description adds substantial value on top: the data is historical and partial, scoped to a 500 m radius, carries no current-provision guarantee, and nulls mean 'unknown' rather than 'absent'. The null-semantics warning is exactly the kind of interpretive context an agent cannot get from annotations or schema.

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 sentences, tightly front-loaded: scope first, caveat second, null semantics last. Nothing is padded, though the brevity leaves documented gaps elsewhere.

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 output schema exists, so return values need not be described, and the behavioral caveats are strong. But with 0% schema description coverage and no usage guidance, the description omits the most critical information an agent needs to invoke the tool correctly: what street_id must look like and what the dimensions argument controls.

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% across two parameters. The description indirectly implies street_id resolves to a 'stored centroid' but never names or constrains the parameter, and it says nothing at all about 'dimensions' and the four service categories it accepts. With no schema documentation, the description should compensate and does not.

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 the data source and scope (partial historical OSM observations within 500 m of the stored centroid), so an agent can infer it returns a single street's context. However, it never states the operation directly ('returns ... for street_id') and gives no differentiation from siblings like callejear_compare_streets or callejear_get_coverage. Purpose is implied rather than declared.

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?

There is no when-to-use guidance, no mention of when to prefer this over get_coverage or compare_streets, and no indication of when the dimensions parameter should be supplied. The description only filters how to interpret output, not when to invoke the tool.

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