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

Annotations already declare readOnlyHint=true, so the safety profile is covered; the description adds non-obvious behavioral context by specifying that results are live (not cached) and ranked by fit, and what metadata each result carries. It does not cover edge behavior such as zero-match responses or ranking criteria, keeping 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?

A single front-loaded sentence keyed to 'WHEN TO CALL', with no filler. It is slightly dense and run-on by the end (three clauses about return shape), but every clause carries 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?

With no output schema, the description correctly spends its words on the return shape (ranked tools, input schema, connection endpoint, free/paid status) so an agent knows it can act on results immediately. Gaps are minor: nothing about no-match handling or how ranking is determined.

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 query, limit and category are already documented, including defaults and max. The description's query examples duplicate the schema's own example ('send an email' vs 'send a slack message') and it says nothing about limit or category, so it adds little beyond the schema.

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 ('discover') and resource (tools) plus the exact input form (plain-language query) and output form (ranked tools with schema, endpoint, pricing). It explicitly distinguishes itself from route_task's single pick, so an agent can separate it from the closest sibling without reading either 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?

Opens with an explicit WHEN TO CALL condition ('you need a capability and don't know which tool provides it') and names the alternative (route_task) with the deciding criterion: several options vs a single pick. No inference required.

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