read_session

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

No annotations are provided, so the description must fully convey behavioral traits. It states 'Read' (implying non-destructive) but does not disclose permission requirements, error handling for invalid session IDs, or details about the output format, despite an output schema existing.

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?

The description is extremely concise: two sentences with parameter details in a clean arglist format. Every word serves a purpose, and the main action is stated first. No redundancy exists.

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?

Given the existence of an output schema, the description doesn't need to detail return values. However, it lacks important context like how many events constitute 'recent', the effect of no session ID, or how this tool relates to get_session_events. It is adequate for a simple tool but leaves gaps.

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 schema description coverage is 0%, so the description must compensate. It explains that session_id is 'The session ID' and last_n is 'Number of recent events to return (default 20).' This adds value beyond the schema's type/title, but the explanations are minimal and do not provide richer context like valid ranges or format constraints.

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 description clearly states the tool's purpose: 'Read recent conversation from a Claude Code session.' It uses a specific verb ('Read') and a distinct resource ('recent conversation') that differentiates it from sibling tools like get_session_events and get_session_info.

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?

The description includes parameter details but provides no explicit guidance on when to use this tool versus its siblings. There is no mention of prerequisites, limitations, or scenarios where an alternative would be preferred, leaving the agent to infer usage from the name.

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