url_decode

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

With no annotations provided, the description carries the burden of disclosing behavior. It explains that mode=component maps to rawurldecode and mode=form interprets '+' as space, which are meaningful behavioral nuances. It does not discuss error handling or output format, but for a simple decoding tool this is adequate context.

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 sentences, front-loaded with the core action, no filler. The mode explanation is compact and directly tied to parameter values.

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 two-parameter tool with no output schema, the description is sufficient: it states the purpose, identifies the required input, and details the optional mode. Minor omissions (e.g., error behavior) are not critical for this utility tool.

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 0%, so the description must add meaning. It adds clarity to the mode parameter by defining the enum values and their effects. It also clarifies 'encoded' via 'percent-encoded URL string', though the schema property name was already self-explanatory.

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 begins with 'Decode a percent-encoded URL string', clearly stating the verb and resource. It also distinguishes between two decoding modes (component/form) and naturally separates itself from sibling tools like url_encode and base64_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 implicitly implies when to use the tool (when a percent-encoded URL string needs decoding) and explains mode options, but it does not explicitly mention alternatives or exclusions. Lacks explicit guidance on when to choose this over url_encode or base64_decode.

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