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

Annotations already flag destructiveHint=true and idempotentHint=true; the description adds the specific mechanics of that destruction (an omitted cap is cleared, so anything not passed is wiped) plus the auth requirement (project Admin). This is meaningful context beyond the bare hints.

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 sentences, front-loaded with purpose, then the destructive interaction rule, then the permission requirement. No filler; 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?

For a 3-param mutation tool with no output schema, the description covers purpose, replace semantics, and auth needs, and the schema fully documents each parameter. The only minor gap is no mention of the failure mode (e.g. what happens if the slug is wrong).

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 the baseline is 3, but the description adds the set-together/omit-clears interaction that governs how all three parameters behave collectively — semantics the per-property schema text does not convey.

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?

Specific verb+resource: it sets a project's monthly ingestion and credit caps, and names both cap types explicitly. No sibling tool (update_project, admin_grant_credits) does this, so an agent can identify it without opening the 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?

Gives the crucial replace semantics — 'Both are set together, so a cap you omit is cleared; pass the one to keep as well' — which tells the agent how to call it safely. It also states the Admin prerequisite. It stops short of naming when to prefer another tool, but no obvious alternative exists.

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