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

With no annotations provided, the description carries the full behavioral burden and supplies almost none. The word 'read' weakly implies a non-mutating operation, but there is no mention of permissions, cost, rate limits, or what the returned 'coverage and limits' structure contains.

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?

It is a single short sentence with no filler, so structure is fine, but the brevity reflects under-specification rather than efficient information density. Every word earns its place only because there are so few words.

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 zero-parameter tool with no annotations and no output schema, the description should at minimum explain what 'coverage and limits' refers to and what form the result takes. It states neither, so an agent cannot predict the return value or confirm the tool fits its need.

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 defines zero parameters, so there is nothing for the description to clarify; baseline 4 applies. No parameter-oriented guidance is needed or missing.

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 largely restates the tool name 'coverage' with the vague qualifier 'read surface coverage and limits'. It does not specify which resource's coverage, what a 'read surface' is, or how it differs from siblings like verify or specimen, leaving the agent to guess at the tool's actual output.

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?

No when-to-use guidance, no conditions, and no mention of the sibling tools (carrier_record, verify, specimen) that might overlap. The agent receives no signal about when this tool is appropriate versus the others.

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