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

No annotations are provided, so the description must disclose behavioral traits. It only states 'percent-encode' without specifying which characters are encoded, encoding for spaces (%20 vs +), or Unicode handling. This is insufficient for safe invocation.

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 a single short sentence, which is concise and front-loaded. However, it could include additional critical details without being overly verbose, so it's not a perfect 5.

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?

Given the tool's simplicity (single param, no output schema) and no annotations, the description provides the minimal necessary information. However, for complete guidance, it should mention encoding behavior and input expectations.

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 has one parameter 'text' with 0% description coverage. The description adds no semantic meaning about the parameter, such as expected format (e.g., raw string vs pre-encoded component), or whether it should be a full URL or just a component.

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?

Description 'Percent-encode URL component' is concise and explicitly states the verb (encode) and resource (URL component). It directly distinguishes from sibling tools like url_decode, url_normalize, etc.

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?

No explicit guidance on when to use this tool versus alternatives such as url_parse or url_normalize. The description implies its use for encoding URL components but lacks context about encoding full URLs vs components or handling special cases.

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