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

No annotations are provided, so the description must carry behavioral disclosure. It usefully states that it uses standard encodeURIComponent rules and includes the cost ($0.001/call), but it does not describe error behavior for malformed decode input or explicitly confirm the operation is stateless/read-only.

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 front-loaded with the core encode/decode behavior in two efficient sentences. The trailing price line is relevant but feels slightly appended rather than integrated, keeping it just short of a 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?

For a simple stateless encode/decode utility with full schema coverage and no output schema, the description is mostly complete. It explains the operation and the encoding standard, but could be more complete by noting return value expectations or decode error behavior.

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%, so the schema already documents both required parameters (op enum and text). The description adds no syntax, format, or edge-case meaning beyond what the schema provides, making the baseline 3 appropriate.

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 states a specific verb and resource: percent-encode or decode text for URL/query-string safety. It is clear what the tool does, but it does not explicitly differentiate from nearby siblings like dev_url_parser, dev_url_reader, or dev_base64_encode.

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 implies usage by saying 'for safe inclusion in URLs and query strings' and 'decode percent-encoded text back,' but it gives no explicit when-to-use, when-not-to-use, or alternative-tool guidance. The agent must infer from the tool name and purpose.

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