lookup_html_entity

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 states the tool is for lookups, implying it is read-only and non-destructive, but does not explicitly mention safety, side effects, or any required permissions. This is adequate for a simple read operation but lacks details like rate limits or data freshness.

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 extremely concise: two sentences followed by a parameter list. The key information is front-loaded. The parameter list is somewhat redundant with the schema but does not detract. It could be slightly more structured (e.g., separating usage notes), but overall it is efficiently written.

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 that an output schema exists (not shown), the description does not need to explain return values. The tool is simple—a single optional parameter with a clear default behavior. The description sufficiently covers input semantics and result expectations for a lookup tool, and the context signals indicate no additional complexity.

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?

The schema description coverage is 0%, but the tool description adds meaning to the 'entity' parameter by calling it a 'Search term' and contextualizing it with the purpose description that mentions 'name, code, or character.' It also explains the behavior when the parameter is left empty. This adds significant semantic value beyond the raw schema.

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 tool's function: 'Look up HTML entities by name, code, or character.' It also specifies the behavior when the parameter is empty ('Leave empty for full list'), which defines the scope and differentiates from sibling tools that are unrelated to HTML entity lookup.

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 provides guidance on when to use the tool (for HTML entity lookups) and gives a specific usage instruction: leaving the parameter empty returns the full list. However, it does not explicitly mention when not to use it or provide alternatives, which is acceptable given the specificity of the tool.

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