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

With no annotations, the description carries the full burden and does well: it discloses the ranking factors, that turned_away stores are returned with reasons, that blocked stores rank last and default to excluded, and that the tool is index-only and never crawls. It omits auth/permission requirements and any latency or freshness characteristics, which keeps it short of a 5.

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 core question, then inputs, then return shape, then a one-clause caveat ('Index only; never crawls'). Sentences are dense but every clause carries information; the ranking-factor list is long but tells the agent how results are ordered.

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 10-parameter, no-output-schema tool, the description covers the return payload (stores with evidence URL, ranking dimensions, plus turned_away with reasons) and the key defaults. Nothing critical is missing, though the meaning of the pay enum and the limit parameter are only covered by the schema.

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 70%, and the description adds real meaning beyond it: category accepts product words that resolve to a finer sub, zip adds landed cost per store, guest excludes account-required stores, and the two include_* flags have documented defaults and semantics. pay, limit, and domain are left to the schema, which is acceptable given their self-explanatory enums/types.

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: find in-map stores that sell a given product family, with a clear 'where else can my agent buy this' framing. It distinguishes itself by scope (index-only, alternative stores) but never names the sibling tools (search_merchants, find_agent_native, check_domain) it complements, so differentiation is inferential 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?

Explains the accepted inputs clearly (a blocking domain and/or a category or product word) and states the product-word resolution rule (headphones -> audio). It also gives conditional guidance for include_indirect ('with pay=btc/lightning') and the default for include_blocked. What's missing is explicit routing: no statement of when to prefer this over search_merchants or find_agent_native.

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