list_sessions

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

readOnlyHint=true already covers the safety profile, and the '[READ]' tag merely repeats it. The description does add value by disclosing what it returns (per-command counts) and that it flags sleeping sessions, but it says nothing about limits, row counts, or whether listing is expensive on a busy server.

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?

Short, front-loaded, and organized into a one-line summary plus a flagged behavior and an Args block. No filler sentences; only minor redundancy in the '[READ]' tag duplicating the annotation.

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 and only two optional parameters, the description covers purpose, return content, and both params adequately. Residual gaps are limits/pagination and target resolution, which are minor for a simple read-only listing tool.

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 0%, so the description must compensate, and it does: include_sleeping is explained with its default (True) and target is explained as a config name to omit for the default. Both parameters are covered, though 'target' syntax/resolution is not spelled out.

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 and resource ('Current sessions (processlist)') plus the return shape ('per-command counts'), which distinguishes it from sibling diagnostics like connection_stats. It does not explicitly name a sibling it replaces, so it stops short of a 5.

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?

Usage is only implied: the parenthetical 'connection-pool leak suspects' hints at a sleep-detection scenario, and the arg notes explain defaults, but there is no statement of when to choose this over connection_stats or long_running_queries.

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