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

No annotations are provided, so the description carries the full burden. 'Percent-encode a string' states the basic action but does not disclose important behavioral details such as whether non-ASCII characters are UTF-8 encoded, whether spaces become %20 or +, or if reserved characters like '!' and '~' are encoded. An agent cannot predict the exact output format without external knowledge.

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 concise sentence with no filler. It is front-loaded and immediately communicates the core action, and there is no wasted text. It earns its place, though the brevity comes at the cost of missing behavioral details captured in other dimensions.

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 tool is simple (one string parameter, output schema present), but the description leaves key ambiguity about the encoding algorithm. With no annotations and zero parameter coverage, the agent is missing guidance on what gets percent-encoded and how. The output schema exists but does not clarify the encoding rules, so the description is not complete enough for reliable invocation.

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 compensate for the single 'text' parameter. It simply says 'a string', which confirms that the parameter is the input string but adds no details about limits, allowed character sets, or how the encoded value relates to the output. The parameter name and type are already self-explanatory from the schema, so the description contributes minimal extra meaning.

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 ('percent-encode') and a resource ('a string'), making the operation clear. It is implicitly distinguished from siblings like url_decode and url_parse by the encoding focus, but it does not explicitly name alternatives or edge cases. Overall, an agent can tell what the tool does without opening the schema.

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?

There is no guidance on when to use this tool versus url_decode, url_parse, base64_encode, or other encoding tools. The description gives no context about appropriate scenarios, format expectations, or exclusions, leaving the agent to infer usage from the tool name alone.

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