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

Annotations cover the safety profile (readOnly/idempotent/non-destructive), and the description adds substantial behavior on top: acknowledged and won't-fix items are counted as excused rather than fixed, scoreBlocker fires when the score alone makes the scan Not ready, minSeverity:critical narrows the list while counts stay complete, and site text is untrusted data. That is exactly the extra context the annotations cannot carry.

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?

Front-loaded with the core rule and dense with signal, but the tail mixes return-value facts, reporting imperatives, and a prompt-injection warning into one long paragraph, which costs some scannability. Nothing is purely filler, though several sentences are agent-behavior instructions rather than tool semantics.

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?

For a two-parameter read tool with no output schema, the description discloses what comes back (readiness, effectiveReadiness, counts) and covers the important edge case that zero blockers is not launch approval, plus the untrusted-content caveat. An agent has everything needed to call it and interpret the result.

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 description coverage is 100% and the description largely restates the schema's minSeverity semantics ('critical lists only Block Launch items') plus the scanId origin. It adds no syntax or format detail beyond the schema, so the baseline 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?

States a specific verb and resource ('What blocks launch on a completed scan') and defines the exact rule: critical and high findings not acknowledged or marked won't-fix. That definition immediately distinguishes it from the sibling list_findings, which returns all findings regardless of state.

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 clear sequencing guidance ('Report blockers before anything else') and explains the minSeverity branch so the agent knows which mode to pick. It does not explicitly name a sibling (e.g. list_findings) as the alternative when the agent wants unfiltered findings, so it stops short of full routing guidance.

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