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

Annotations already declare this as a non-read-only, non-destructive, non-idempotent write, so the bar is lower. The description goes beyond them by disclosing the optimistic-concurrency contract - expectedSpecVersion exists to prevent stale writes - which an agent could not infer from the annotations or schema. It omits what happens on a version mismatch, so it is not a full 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?

Two short sentences, no filler. The purpose is front-loaded and the concurrency constraint follows immediately; every clause 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?

A mutation tool with a nested input object, 3 required parameters, and no output schema. Purpose and the concurrency contract are covered, but permission/authorization requirements, failure behavior on version mismatch, and the meaning of projectId are absent.

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?

Top-level schema coverage is 0%, but the description compensates for expectedSpecVersion by explaining its purpose. projectId is left entirely unexplained in both description and schema, and the expression DSL shape is conveyed only structurally by the anyOf. Baseline 3 is appropriate given the description covers one of the three top-level parameters.

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?

States a specific verb+resource: configuring computed feature fields and expressions on a project map. The domain is narrow enough to be told apart from the configure_legend / configure_popup / configure_bubbles siblings. It does not explicitly name or contrast with any alternative tool, so it stops short of a 5.

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?

Usage is only implied by the phrase 'for a project map'; there is no explicit when-to-use, when-not-to-use, or routing to a sibling (e.g. update_layer_style for appearance). The one operational precondition given (expectedSpecVersion required) is useful but is a requirement, not usage guidance.

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