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

Annotations already declare readOnly, idempotent and non-destructive, so the description only needs to add context. It does so usefully by disclosing that an unrecognised slug silently matches nothing instead of erroring — a real failure mode an agent would otherwise miss — and by noting the result is a short summary per DJ. Pagination and total-count behaviour are still unstated.

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?

Four sentences, front-loaded with purpose and followed by the routing rule and the slug caveat. No filler; every sentence changes how the tool would be called.

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 12-parameter, no-required-field search tool with no output schema, the description covers purpose, sequencing, parameter format constraints and the shape of the response. Minor gaps remain around result volume and how the limit interacts with total matches, but nothing essential to correct invocation 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 coverage is 100%, so the baseline is 3, but the description adds cross-parameter meaning the schema does not: genre, occasion and extra must be slugs, they are sourced from list_reference, and invalid values fail silently. That contextualizes three of the twelve parameters beyond their individual descriptions.

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 DJs on DJfindr") plus the filter axes it supports, and explicitly separates itself from get_dj, which needs an id or slug. An agent can distinguish it from siblings like get_dj or list_reference without opening a 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?

Gives explicit routing advice: "This is the starting point for almost any request: call it before get_dj, which needs an id or slug this returns." It also names list_reference as the source of slug values and warns to verify rather than guess, covering both when to use it and how to prepare the call.

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