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

Annotations already declare readOnlyHint=true, openWorldHint=true, and destructiveHint=false, so the safety profile is covered. The description adds the non-obvious behavioral fact that non-'web' source ids are rejected, but says nothing about result format, pagination, or latency/rate behavior.

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 short sentences with the tool's action front-loaded and the source restriction immediately following. No filler beyond the minor branding mention of 'Desearch'.

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 simple read-only search tool with rich annotations and a fully documented schema, this is adequate but thin. With no output schema, the description could have sketched what a result looks like, and it offers no context on how it differs from the many sibling search tools.

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 the schema documenting count bounds, the tools enum/default, and a prompt example, so the baseline is 3. The description adds nothing beyond the schema for parameters.

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 ('search the web for links') plus the backend (Desearch), which is enough to identify it as a general web link search. It does not explicitly name the sibling it contrasts with (e.g. x-links-search or web-search), so an agent must infer differentiation from the namespace.

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 constraint 'Only the web source is accepted' implicitly tells the agent not to use this for X/Twitter link search, which is useful negative guidance. However, it never states when to prefer this over siblings like web-search, ai-search, or web-crawl, so selection guidance is only implied.

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