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

Beyond the annotations (readOnly, idempotent, non-destructive), the description discloses additional behavioral details: 'no fetch to any site, no quota', the authoritative-grade semantics with explicit handling of unscored newer attempts, and the empty-list response instead of an error. These details meaningfully enhance transparency.

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 verbose and contains redundancy, such as repeating 'the same definition the web panel and the badge use' and restating idempotency and read-only behavior which are already in the annotations. While the structure uses clear sections, several sentences could be trimmed without losing meaning.

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 fully covers the tool's context: its purpose, output fields, edge cases (empty list, unscored newer attempts), and limitations (no fresh measurement, account scope, no mutation). Given the absence of an output schema, this prose provides a complete picture of what the caller can expect.

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 no properties and coverage is 100%, so there is little to add. The description goes slightly beyond by explicitly stating 'PARAMETERS: none — this tool takes no arguments; call it with an empty arguments object', which reinforces the calling convention in prose.

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 primary function: 'Lists the sites saved on the authenticated Lekta account' and enumerates the returned fields (URL, grade, score, last audit, recheck interval). It also differentiates itself from siblings by calling it 'account inventory, not a measurement' and by contrast with lekta_audit.

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 explicitly instructs when to use this tool: 'USE THIS first in a session to see which URLs this account already tracks before picking one to pass to lekta_audit, lekta_fix_plan or lekta_diff'. It also states when not to use it, e.g., 'DO NOT expect a fresh measurement (lekta_audit does that)' and clarifies account scope and panel-based management.

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