agent_read

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

With no annotations, the description carries the full behavioral burden and does a fair job: it explains what content is returned for each session type and that wait_idle blocks, which reaches beyond the schema's terse 'wait for output to stop changing'. It omits anything about permissions, failure modes, or the interaction between wait_idle here and the separate agent_wait_idle tool.

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 core action, followed by per-session-type content and then the wait behavior. No filler sentences.

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 4-param read tool with no output schema and no annotations, the description covers the essential unknowns: what the returned content actually is per session type and what blocking does. It stops short of explaining return shape/pagination or how this differs from agent_transcript and agent_wait_idle.

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 schema already documents lines, session, wait_idle and idle_timeout_ms. The description's explanation of wait_idle largely restates the schema's own text, adding tone but little new semantic detail, so the baseline 3 applies.

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?

Names a specific verb and resource (read recent output of a session) and even disambiguates what 'output' means per session type: tmux screen minus TUI chrome vs a Claude background session's log. It does not explicitly contrast with the overlapping sibling agent_transcript, so sibling differentiation is implied rather than stated.

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?

It tells the agent when to set wait_idle: true (to block until output stops), and a separate agent_wait_idle sibling exists that is never mentioned, nor is agent_transcript for full history. Usage context is implied rather than spelled out as when-to-use / when-not-to-use.

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