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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, covering the safety profile. The description adds meaningful context beyond this, including the specific returned fields and the reliability claim that it 'Never fails for a valid key.' This goes beyond what annotations provide.

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?

The description is longer than average but well-structured: primary purpose first, then usage guidance, then alternatives, then return fields. The enumeration of return fields is justified because there is no output schema, and no sentence is wasted.

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 read-only, parameterless tool with rich annotations, the description is complete. It explains why and when to call it, what it returns in detail, how it relates to relevant siblings, and its failure behavior, leaving no significant gap for an agent deciding to invoke it.

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?

The tool has zero parameters and the schema is entirely covered by an empty properties object. Per calibration, a 0-parameter tool gets a baseline of 4; there is no parameter-level meaning for the description to add.

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 and resource: 'Return the workspace's plan, monthly publish quota, usage and feature flags.' It clearly distinguishes itself from sibling tools by naming get_rate_meter and get_account_analytics as alternatives for different purposes.

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?

Explicit guidance is given: use before a large create_pins_batch, after quota_exceeded, or to check plan features before upload_asset and create_pins_batch. It also explicitly routes the agent to get_rate_meter for per-account publish rate and get_account_analytics for pin performance, providing clear when-to-use and when-not-to-use instructions.

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