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

Annotations already carry the safety profile (readOnlyHint, idempotentHint, destructiveHint=false), and the description's 'Read-only' merely restates them. It does add a non-obvious behavioral caveat — that a returned listing does not imply the item is stocked — which prevents a real misinterpretation, but it says nothing about ordering, pagination, or failure modes.

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 tight sentences: resource/scope first, then the safety note, then return fields and the sibling relationship. Every clause carries new information with no padding.

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?

With an output schema present and rich annotations, the description only needs to supply purpose, sibling routing, and semantic caveats — all of which it does. Nothing an agent needs to select and invoke this tool correctly 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 name, zip, market, and limit are all documented with examples and defaults. The description echoes the zip-or-market locator choice but adds no format, precedence, or constraint detail beyond the schema, so the baseline of 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+resource (find local shops) with the two supported locators (US ZIP code or served market), and immediately distinguishes itself from search_catalog. An agent can tell what this returns without opening the schema.

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?

Names the alternative tool explicitly and gives the handoff rule: pass store_id to search_catalog to scope a catalog search to one shop. It also sets a use boundary — 'A listing here proves no stock' warns the agent not to treat this as an inventory check, routing that need to search_catalog.

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