Rival listing changes

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

Annotations already declare this as a safe read-only, idempotent, closed-world operation, so the burden is lower. The description adds meaningful context beyond the annotations: changes are captured only when a listing is re-read on every rank check, and results are newest-first with specific field semantics.

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?

A single dense sentence that front-loads what the tool returns and then layers timing, ordering, and field breakdown. It is efficient, though the run-on structure with multiple parentheticals makes it slightly harder to scan than it could be.

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?

With no input parameters and no output schema, the description carries the return-value explanation and does so adequately: it names the record fields and the capture cadence. Only the absence of any sibling/alternative routing keeps it from a 5.

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?

This tool has zero input parameters, so the baseline is 4. The description properly spends its words on output shape (app, locale, field, from -> to, read) rather than inventing parameter guidance that does not exist.

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?

States a specific verb (list) and resource (name/subtitle changes of tracked rivals, kind competitor), plus ordering and returned fields. It implicitly separates itself from rank-alert tools by focusing on listing renames rather than rank movements, though it never names a sibling explicitly.

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 closing line gives one actionable context — a rival renaming around a phrase is a cue to re-check that phrase — but there is no explicit when-to-use/when-not guidance and no named alternative among the many sibling list_* tools.

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