coverage_map

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

With no annotations, the description carries the full disclosure burden. It openly states 'Read-only', clarifies the tool is deterministic, and defines its scope ('measures what the graph contains'). It lacks details on response formatting or error behavior, but for a reporting tool the key behavioral traits are covered.

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?

Three sentences with no filler. The read-only flag is front-loaded, the purpose is stated immediately, and the use-case guidance earns its place. Nothing is redundant.

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 description covers purpose, read-only behavior, scope boundaries, a decision-oriented use case, and parameter optionality. With no output schema, it does not need to detail return values; the format parameter already hints at text vs json output. Missing an explicit note on pagination is a minor gap.

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%, so the schema already documents limit, format, offset, and component_depth. The description adds only 'All params optional' and contextual meaning ('by component'), which is useful but not enough to push above the baseline.

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-resource pair ('Report deterministic graph coverage by component') and enumerates concrete outputs (files, callable bodies, diagnostics, unmodeled frontiers). It also distinguishes itself from per-client session activity, so an agent can tell it apart from activity-tracking siblings.

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?

It gives a clear when-to-use trigger: 'use it to decide whether an empty result means clean or not analyzed'. It also states a what-not-for condition ('not per-client session activity'). However, it does not name any sibling tool as an alternative, so the guidance is good but not fully explicit.

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