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

With no annotations, the description must carry the full burden. It discloses the HTTP method, the endpoint, and notes that 'this MCP door does not charge,' which is a useful behavioral fact. However, it omits the actual effect of the operation, any side effects, authentication requirements (though X-AGENT-ID is named, it is not explained), and what the agent receives as a result.

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 brief, two sentences, and gets to the point. The HTTP method and endpoint are front-loaded. However, the phrase 'with { payer }' appears without context, and the note about not charging is a bit tangential. Still, it is appropriately compact for a simple tool.

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 (1 parameter, no output schema), so the description should be sufficient on its own, especially without annotations. But it lacks a clear statement of purpose, the meaning of the parameter, and the expected result. The mention of an unlisted 'payer' further degrades completeness.

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 has a single required parameter 'id' with 0% description coverage. The description mentions '{ payer }' which is NOT in the schema, creating confusion and implying an undocumented parameter. It provides no explanation of what 'id' refers to or how it is used, and the X-AGENT-ID header is not a parameter. The description fails to add clarity and instead introduces a conflicting piece of information.

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 noun/verb pair: 'unlock' a handoff via an HTTP POST endpoint. It is distinguishable from siblings like 'discover' or 'status'. However, it does not clarify the semantic effect of unlocking (e.g., releasing a hold, enabling access), which leaves some ambiguity.

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 offers no guidance on when to use this tool versus alternatives. There is no mention of conditions, exclusions, or comparisons with the sibling tools. The only contextual hint is 'HTTP pointer only,' which implies a technical constraint but not a selection criterion.

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