url_decode

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

Without annotations, the description fully covers behavior: pure local decode via decodeURIComponent, no network calls, success returns decoded string, failure returns error message. It also clarifies handling of both encoding formats. This is sufficient transparency.

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?

The description is four sentences, each serving a purpose: action, use cases, implementation detail, and failure mode. It is front-loaded with the primary action and wastes no words.

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 tool with one parameter, no output schema, and no annotations, the description covers all necessary context: what it does, when to use, how it works, and what happens on failure. It 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 description coverage is 100%, and both schema and tool description provide examples and guidance (e.g., 'Pass only the encoded component, not a full URL'). The tool description adds a small extra nuance beyond the schema, but not significantly.

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 the verb 'Decode' and specific resource 'percent-encoded URL component', with examples of use cases (query parameters, path segments, form-encoded values). It is distinct from siblings like url_encode, base64_decode, and jwt_decode.

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 when to use this tool: to read query parameters, path segments, or form-encoded values. It also notes that it accepts both + and %20 encodings. However, it does not mention alternatives or when not to use it, but the sibling list provides implicit distinction.

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