Url Redirects

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

Annotations already indicate readOnlyHint, idempotentHint, and destructiveHint. The description adds beyond this: 'it does not execute JavaScript or bypass access controls', and implies safety validation through SSRF rejection. No contradictions with annotations.

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?

Three sentences, each carrying distinct information: purpose, constraints, and caching guidance. Front-loaded with the core action. No fluff.

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?

The description fully covers the tool's behavior: input requirements (public HTTP only, absolute URL), safety validation, caching semantics, and what it does not do. With an output schema present, the description is 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 coverage is 100%, so the baseline is 3. The description adds marginal value: for url it restates the absolute public URL requirement, and for fresh it adds 'cheaper for the origin' context. This is helpful but not a significant extension beyond the schema 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?

The description clearly states 'Return the safely validated redirect chain', specifying a concrete verb and resource. It also distinguishes from sibling URL tools by emphasizing that it only handles redirects and does not execute JavaScript, making the tool's unique purpose obvious.

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 description explicitly says 'Use only for public HTTP(S) resources' and instructs on when to set fresh=true vs false. While it doesn't name specific sibling alternatives, the constraints effectively guide when to use this tool versus other URL inspection tools.

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