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

Goes well beyond the annotations by disclosing the key non-obvious behavior: writes silently succeed but do NOT persist, which sibling tools are unaffected, and that the flag resets to off on session reconnect because it is not persisted. These are exactly the behavioral traits an agent needs and none are derivable from the schema or annotations.

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?

Three tight sentences, front-loaded with the action, then the effects, then the lifecycle caveat. No filler and every clause conveys actionable 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?

For a one-boolean toggle with no output schema, the description covers everything needed: what it does, what it suppresses, what it leaves alone, and when it resets. Nothing required to invoke it correctly is missing.

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% and the parameter is a single boolean, so the baseline is already met. The description adds real semantic content by spelling out the consequence of on=True versus the implicit off state, giving the parameter meaning beyond the schema's tautological 'True to enable ghost mode'.

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 pair (enable/disable), the resource (ghost mode), and its scope (this session). It also anchors the concept by naming the sibling tools it affects (store_fact, store_session_summary, search_facts), so an agent can place it immediately against the rest of the toolset.

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?

The description makes the operational context clear: enabling ghost mode turns store_fact and store_session_summary into silent no-ops while reads keep working normally, which strongly implies a dry-run/do-not-persist scenario. It does not, however, give explicit 'use this when/do not use this when' phrasing or name an alternative tool for the same goal.

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