angle

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

Annotations already declare readOnlyHint=false, idempotentHint=true and destructiveHint=false, so the agent knows this creates something without destroying data. The description usefully discloses the side effect (it draws a persistent named angle object) and the units (degrees). It does not say whether an existing object with the same name is overwritten, nor what happens if a selection is empty or degenerate.

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, front-loaded with the measurement result and followed by the side effect. No filler, no restatement of the tool name, and every clause carries 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?

An output schema exists, so the description need not explain return values, and the parameters are fully documented in schema. For a non-destructive, idempotent geometry tool this is close to complete; only overwrite/naming behavior and failure modes are unstated.

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 each parameter already documents its role (arm, vertex, arm, name), so the schema carries the semantics. The description adds only the aggregate fact that exactly three selections are consumed and that 'name' labels the drawn object — no extra meaning beyond the schema. 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?

States a specific verb and resource: 'Measures the angle between three selections and returns it in degrees', plus a side effect ('draws the measurement as a named angle object'). An agent can tell this is an angle-measurement tool, but the description never names the obvious sibling alternative (dihedral, for four-atom torsion), so differentiation is left implicit.

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?

There is no when-to-use or when-not-to-use guidance: nothing says to prefer this over dihedral or distance, and nothing states the prerequisite that three atoms/selections must already exist. The agent must infer usage entirely from the name and the one-line purpose.

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