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

Annotations already declare readOnlyHint=true, openWorldHint=false, destructiveHint=false, so the safety profile is covered. The description adds genuine behavioral context beyond that: the automatic project-selection fallback when projectIds is absent or singular, and the shape of the comparison output.

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, zero filler, with the primary purpose front-loaded and the two usage modes following in order of importance. Every sentence earns its place.

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 an output schema present, the description need not detail return values, yet it still summarizes them usefully. For a two-parameter, zero-required, read-only comparison tool, nothing an agent needs to call it correctly is missing.

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%, so baseline is 3, but the description adds a real threshold not stated in the schema: that explicit comparison requires at least two projectIds, while one or zero switches to auto-discovery. That is meaningful semantics beyond the parameter descriptions.

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 and resource ('Compare feedback across projects') and elaborates with the two operating modes, so the agent knows exactly what the tool produces (headline plus shared/divergent themes). It does not, however, explicitly contrast itself with the sibling 'similar_projects', which is the closest potential confusion.

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?

Gives concrete invocation conditions: 2+ projectIds for an explicit comparison, one or none to trigger auto-discovery of comparable projects. This is clear operational context, but it never states when to prefer this tool over alternatives such as similar_projects or project_overview.

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