w3c-mcp

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It states what the tool does but doesn't describe how it behaves: e.g., whether it returns structured data or raw text, if there are rate limits, authentication needs, error handling, or pagination. For a tool with no annotation coverage, this leaves significant gaps in understanding operational traits.

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, efficient sentence that front-loads the core purpose ('Get HTML element definitions') and adds necessary scope ('from a specific spec or all specs'). There's no wasted language, repetition, or unnecessary elaboration, making it easy to parse and understand quickly.

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 no annotations, no output schema, and 2 parameters with full schema coverage, the description is incomplete. It lacks details on return values, error conditions, behavioral constraints, and differentiation from siblings. For a tool in a context with multiple similar tools (e.g., 'list_element_specs'), more guidance is needed to ensure the agent can use it effectively.

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%, with clear descriptions for both parameters ('spec' and 'element'). The description adds minimal value beyond the schema, as it only implies the optional nature of 'spec' ('If omitted, returns all elements') without detailing parameter interactions or examples. Baseline 3 is appropriate since the schema does the heavy lifting, but the description doesn't enhance parameter understanding significantly.

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 action ('Get') and resource ('HTML element definitions') with scope ('from a specific spec or all specs'). It distinguishes from siblings like 'get_css_properties' by focusing on HTML elements rather than CSS properties, but doesn't explicitly contrast with 'list_element_specs' which might overlap. The purpose is specific and understandable, though sibling differentiation could be more explicit.

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 no guidance on when to use this tool versus alternatives like 'list_element_specs' or 'search_w3c_specs'. It mentions the scope ('specific spec or all specs') but doesn't explain use cases, prerequisites, or exclusions. Without such context, the agent lacks clear direction for tool selection among similar siblings.

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