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

Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds genuinely new behavioral context: matching is deterministic and case-insensitive, contains/not_contains have AND/OR semantics, and '*' globs match instance-suffixed tools. It does not say what an update overwrites, but that is a minor gap.

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 sentences, front-loaded with the core action and the update trigger before the matching rules. The second sentence is dense but every clause carries matching semantics an agent needs; nothing is padding.

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 9-parameter write tool with no output schema and annotations already covering safety, the description supplies the non-obvious matching semantics well. It leaves the required name/prompt/agent_id roles entirely to the schema, which is acceptable given 100% coverage.

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 coverage is 100%, so the baseline is 3, and the description earns above that by documenting semantics the schema omits: case-insensitive matching and glob behavior for tool_called. The contains_any/contains_all restatement is redundant with the schema, but the glob and case-insensitivity details are real additions.

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 states a specific verb+resource ('Add a test to the agent's saved suite') and immediately covers the second mode ('or update one (test_id)'), which distinguishes it cleanly from list_tests and run_tests. An agent can tell what this tool does without opening the schema.

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 makes the add-vs-update branch explicit by tying the update path to test_id, which is the key selection decision within the tool. It does not, however, say when to reach for this instead of run_tests or probe_agent, so alternatives remain unaddressed.

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