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

With no annotations, the description carries the full burden and does so: billing (one map request per page), credential binding and 24-hour expiry of group ids, and the auth mechanism (X-API-Key header or env var) are all disclosed. It also explains the conditional presence of `label` based on the source zoom level.

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 purpose sentence, then clearly labeled Returns/Billing/Auth blocks. The Returns block is verbose but justified since there is no output schema; every line carries operational 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?

For a paginated read tool with no output schema and no annotations, the description supplies the return shape, pagination fields, billing cost, credential requirements, and id lifetime — everything an agent needs to invoke and chain it correctly.

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, but the description adds meaning beyond the schema by constraining group_id behavior (valid for 24 hours, only for the issuing account) and clarifying what `named: true` implies about returned labels.

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 ('List the people behind a many-people pin or an approximate-area pin') and clearly distinguishes itself from siblings map_viewport/map_area/map_route, which produce the group ids it consumes.

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 concrete follow-up routing ('Each member id opens with map_open_record') and a recovery path ('after that, call map_viewport again'), plus the 24-hour/account-bound lifetime condition. It stops short of an explicit when-to-prefer-this-over-X statement, but the group-id provenance is clear from context.

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