mind_session

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

With no annotations, the description carries the full burden and does disclose per-action semantics plus that the end summary must be hand-written, free-form, and under 200 words. However it omits edge behavior: calling start when a session is already active, what last returns when no prior session exists, persistence/ordering guarantees, and whether end is irreversible.

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 resource, then the enum breakdown, then the migration note. Every clause earns its place and nothing is padded.

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?

There is no output schema, so the description must convey returns, and it only partially does ('last — read the previous session's summary'); what start and end return, and any error signaling, are unstated. Adequate for the happy path but incomplete for a lifecycle tool with a required enum action.

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%, so the baseline is 3. The description adds only marginal meaning beyond the schema (it restates what each action does and that agent should be consistent across start/end), with no extra constraints such as summary being ignored for actions other than end.

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 resource (the agent's session record across runs) and enumerates the three lifecycle operations with a parenthetical gloss for each. It also explicitly says it supersedes mind_session_start/_last/_end, letting an agent distinguish it from named siblings without opening schemas.

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?

Each action is scoped: start opens a session, last reads the prior session's summary, end closes the active one. That is clear routing guidance for the enum, and the 'Replaces...' clause tells the agent not to reach for the old split tools. No explicit exclusion or prerequisite (e.g. what happens if start is called while one is open) is given.

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