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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is fully covered. The description adds the nature of the output (related plus trending terms), which is useful, but it does not explain the relationship between "trending" and the declared closed-world behavior, nor what is returned when query is 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?

A single sentence with zero filler, front-loaded with the returned resource and followed by the exploratory use case. Nothing is repeated from the schema or annotations.

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 two-parameter read tool with full schema coverage and no output schema, the description covers the essentials. The main omission is behavior when no required parameters are supplied (required=[]), i.e. whether omitting query yields generic trending terms, which an agent would need to know to call it correctly.

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%, with both query and size documented including the default of 6, so the baseline is 3. The description adds no syntax, format, or length constraints beyond restating that suggestions relate to the query.

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?

The description opens with a specific verb and resource ("Return related and trending search terms") and adds the intent ("exploring adjacent styles or alternative phrasings"). It is clear on its own, but it never names or distinguishes itself from the closely overlapping siblings autocomplete and find_similar, so an agent must infer the difference.

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 phrase "for exploring adjacent styles or alternative phrasings" implies a usage context, giving the agent a rough sense of when this fits. However, there are no explicit when-to-use/when-not conditions and no routing to the obvious alternatives (autocomplete, find_similar), which is a notable gap given how similar those siblings are.

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