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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false and openWorldHint=false, so the safety profile is covered structurally. The description adds value beyond that by disclosing the full shape of the payload (side-by-side metrics, per-assistant/topic breakdowns, prompt overlap categories, quoted pages, third-party citations), which is important given there is no output schema. It does not mention cost, latency, or what happens when a competitor has no data, which keeps it just short of a 5.

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 long sentence, but it is front-loaded with the core action and every clause enumerates a distinct section of the return payload rather than padding. Slightly heavier than ideal for scanning, but 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?

With no output schema and only two fully documented parameters, the description carries the return-value burden and does so thoroughly, itemizing every report section. An agent knows what it will get back and when to prefer this over list_competitors.

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 coverage is 100% and both required params (projectId, competitorId) are documented in the schema with their source tools (list_projects, list_competitors). The description adds no additional meaning about these parameters, so the baseline of 3 applies.

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 opens with a specific verb and resource ('Compare one tracked competitor with the brand') and then enumerates exactly what the report contains: headline numbers, per-assistant and per-topic comparisons, prompt overlap buckets, competitor pages quoted, and third-party citations. It also distinguishes itself from the sibling list_competitors by name, so an agent can select it without opening either schema.

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 states the use case explicitly ('Use it to see where and why a rival wins') and routes the agent to the alternative for a different need ('list_competitors gives the overview of all of them'). The when-to-use versus when-to-use-the-sibling distinction is fully resolved in the text.

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