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

Annotations already declare readOnly=true, idempotent=true, destructive=false and openWorld=false, so the safety profile is fully covered. The description only adds that the guide contains sections, tables and related pages, which is largely redundant given an output schema exists. It says nothing about what happens when the material is unknown or omitted.

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 tight sentences with the resource and its valid values front-loaded, and no filler. The second sentence about sections, tables and related pages is marginally redundant with the output schema but not wasteful.

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 rich annotations, a full output schema and fully described parameters, the definition covers purpose adequately. However, for a tool with four alias parameters and zero required fields, the description should clarify whether supplying a material is necessary and how an unknown value is handled; that gap prevents it from being complete.

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%, and the description merely restates the material enumeration already present in the schema, adding no new meaning. It also leaves the key ambiguity unaddressed: four parameters (name, guide, topic, material) are documented as 'same value as material' and none are required, so the agent gets no guidance on which to populate or whether one is mandatory.

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: returns the site's guide for exactly one punch needle material. It enumerates the valid material set (needles, fabric, monk's cloth, yarn, floss, hoops, glue), which separates it cleanly from siblings like get_pattern or match_materials.

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?

The purpose implies when to reach for it (looking up reference material for a given material), but there is no explicit when-to-use vs when-not, and no mention of the other lookup or calculation siblings. The agent must infer the routing itself.

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