agent_limits

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

With no annotations, the description carries the burden and does useful work: it discloses that the check reads the live pane instead of a counter and explains why (banners are UI-rendered and never exposed via API). It omits failure modes (e.g., what happens if no pane/session exists) and cost/latency implications of a pane read.

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?

Two sentences, front-loaded with the outcome, and the second sentence earns its place by justifying the unusual implementation. No filler.

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 no annotations, the description adequately conveys what is returned (limited status plus reset time). Minor gap: no mention of what is returned for sessions with no limit or what happens on read failure.

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 single optional parameter is already documented in the schema, so the baseline is 3. The description adds only indirect context ('a session', 'if so'), not format or scope detail beyond the schema.

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+resource: reports whether a session is rate- or usage-limited and, if so, the reset time. That is concrete and clearly distinct from siblings like agent_read or agent_status, though it never names an alternative tool to sharpen the boundary.

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 implied rather than stated: the agent can infer you call this when you suspect a limit banner, and the schema carries the 'omit to check every tmux session' scope. There is no explicit when-to-use vs agent_read/agent_transcript guidance or precondition.

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