Validate the project

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

Annotations already declare readOnlyHint and idempotentHint, so safety and repeatability are covered. The description adds genuinely useful detail that the check stops at the first problem rather than returning all issues, which an agent needs to know. It says nothing about cost, side effects on the open document, or the shape of the result, so it is a modest addition rather than rich context.

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?

Two tight sentences, front-loaded with what the tool does and followed by the triggering contexts. Every clause carries information, though the 'or confirm that the project is valid' clause slightly restates the first sentence.

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 simple, single-parameter read-only tool the description covers purpose, trigger, and the meaning of a result (first problem vs. valid), which substitutes for the absent output schema. It stops short of indicating what a reported problem looks like or whether validation can be expensive on large projects.

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?

There is one optional parameter and schema description coverage is 100%; the schema already explains that it takes an open project id and defaults to the most recent project. The description adds nothing about the parameter, so 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?

Names a specific verb (validate) and resource (the open project), and specifies the validation engine ('the editor's own document validation'), distinguishing it from anything else in the sibling list. No other sibling performs validation, so the unique role is unambiguous.

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 two concrete triggers: after edits a client rejected, and before saving. That is clear situational guidance with no real alternative to exclude, since no sibling does validation. Lacks any explicit 'not needed when' condition, which is why it falls short of a 5.

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