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

Annotations already declare idempotentHint=true and destructiveHint=false; the description concretizes idempotency ('succeeds whether or not an id was actually a member') and adds cost/behavioral context the annotations cannot express ('no SEO data provider is called and no credits are spent'). It does not describe partial-failure behavior for the array or any auth requirements, so it stops 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?

Three short sentences with zero filler, front-loading the action, then the idempotency behavior, then the cost profile. Nothing repeats the schema or the title.

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 2 required params, full schema coverage, and no output schema, the only real burden is behavioral explanation — idempotency and cost are both covered, and destructiveHint=false is consistent with the fact that projects themselves survive. Minor gap: no mention of how many ids can be processed (the maxItems=100 batch boundary) or of partial success semantics.

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 schema already documents both portfolioId and projectIds, including pointing to list_projects and list_portfolios. The description adds no syntax, limit, or format detail beyond that, 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?

The description opens with a specific verb+resource ('Removes projects from a portfolio'), which an agent can immediately distinguish from the sibling add_portfolio_projects and from delete_portfolio (which removes the whole portfolio). No schema inspection is needed to know what it does.

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 conveys two useful selection signals — that removal is tolerant of unknown ids and that the call is free — but never states when an agent should prefer this over alternatives such as delete_portfolio or add_portfolio_projects. Usage is implied rather than framed as guidance.

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