List sessions

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds the useful behavioral fact that the tool returns every session and surfaces a history cursor and keyed-input handle, but it says nothing about ordering, pagination, result size, or whether all sessions are returned in one call.

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?

A single front-loaded fragment with no filler; each listed field plausibly matters to a caller. It is slightly cryptic in places ('inputInstance for keyed input'), but nothing is redundant.

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?

With no output schema, the description must carry the return-value burden, and it does enumerate the fields. However, it omits ordering, volume/pagination behavior, and any explanation of the history cursor's role, which are material for a zero-argument list tool whose result set could be large.

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?

The tool takes zero parameters and the schema is closed, so there is nothing for the description to disambiguate. Baseline 4 applies; the field list is return-value information rather than parameter meaning.

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 fragment enumerates what each session record contains ('status, recent activity (working), model, sub-agents, latest reply id, history cursor'), which implies a read of all sessions, but there is no verb or explicit statement that this lists sessions. It is interpretable but telegraphic, and it never distinguishes itself from siblings such as start_session or read_replies.

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 guidance at all: no mention of when to call this versus start_session, stop_session, or the read_* siblings. The only implicit signal is 'every session', suggesting no filtering, but an agent must infer the use case.

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