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

Annotations declare destructiveHint=true, and the description complements this by disclosing the legacy lane-key fallback behavior, the experiment-only Ledger coupling, and that the call "May return needs_confirmation" (tying to the approvalId param). It doesn't explain reversibility or what a status change does to dependent data, so it stops short of a 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?

Front-loads the core action and the name-based addressing before the conditional Ledger guidance, and every sentence carries operative information. It is dense-to-long, but 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 mutation tool with no output schema, the description covers the addressing options, the experiment-conditional side effects, and the confirmation return shape. It leaves the mutation's side effects on the change itself unstated, but the essential call-time context is present.

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?

With 100% schema description coverage, the schema already documents every parameter, including the enum values and the status/statusName alternative. The description adds only marginal value by naming example lane keys and default-status landing behavior, 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?

States a specific verb ("Move") and resource ("a change") with the target (one of the workspace's statuses), and clarifies the two accepted addressing modes. An agent can distinguish it from compass_opportunities_update and compass_opportunities_mark_implemented without opening a 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?

Explicitly routes the agent: use compass_statuses_list for names, offer compass_opportunities_register_expectation when an experiment enters In progress without an expectation, and ledger_entries_settle when it enters Done with an open Ledger entry. It also states the negative case ("Other changes just move").

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