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

With no annotations, the description carries the full behavioral burden. It usefully discloses partial-update semantics ('Only the fields provided are changed') and a prerequisite lookup step, but says nothing about required permissions, reversibility, side effects of disabling, or failure modes for a mutation tool.

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 tightly packed sentences that front-load the purpose, then usage, then prerequisite and partial-update behavior. No filler or repetition; every sentence contributes actionable information.

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 5-parameter mutation tool with a fully-described schema and no output schema, the description covers purpose, use cases, prerequisite, and update semantics. It lacks authorization/response details, but those gaps are modest given the schema coverage and lack of output schema.

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%, so the schema already documents each parameter, including uniqueness and null-clearing behavior. The description repeats the field names and adds partial-update meaning, but adds no syntax or constraints beyond the structured 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?

Starts with a specific verb + resource ('Update an existing portfolio') and enumerates the exact mutable fields (name, type, description, enabled state). This clearly distinguishes it from create_portfolio, delete_portfolio, and read-only get_portfolios without needing to name them.

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?

Explicitly states when to use it ('when the user wants to rename, recategorize, or disable') and gives the prerequisite to obtain the portfolioId from get_portfolios first. It does not name alternatives or conditions when not to use it, but the context is clear enough for selection.

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