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

The annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description still adds real context beyond them: the 30-day comparison window and the fact that values come from stored snapshots with no AI involved, which tells an agent the data may be stale and is deterministic. It does not say how to force freshness, but that is what the sibling refresh tool is presumably for.

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 short sentences, front-loaded with the resource name and immediately followed by the definitions an agent needs. Every clause carries information — the time window, the two categories, the per-item fields, and provenance — with no filler.

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 parameters and no output schema, the description carries the burden of describing return content, and it does: a per-competitor set of wins and opportunities, each with a metric and gap size over a 30-day window. What is missing is any sense of scale, ordering, or whether an empty result means 'no competitors configured' versus 'no gaps found' — minor, but an agent would want it.

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 tool takes zero parameters, so there is nothing for the description to disambiguate and the baseline of 4 applies. The description does not invent implicit filters, correctly matching the empty schema.

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 concrete verb+resource (get wins and opportunities) and then defines both terms precisely: wins are where you are ahead, opportunities are where the competitor is, each carrying a metric and gap size. That definition removes most ambiguity. It stops short of naming a sibling (e.g. get_competitor_leaderboard or refresh_market_intel) for contrast, which keeps it from a 5.

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?

Usage is only implied: phrasing the output as 'comparisons already computed' and 'derived from stored snapshots' hints this is a read of precomputed data rather than a recomputation, which subtly points an agent away from refresh_market_intel. There is no explicit when-to-use, when-not-to-use, or prerequisites (e.g. whether competitors must be added first).

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