chat_history_read

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

With no annotations provided, the description carries the full burden of disclosure. It explicitly states 'Read-only' and describes the return structure: 'Returns the resolved file path plus a list of matching entries (newest last).' This covers key behavioral traits without contradictions.

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 concise, using only a few sentences, and front-loads the core action. Every sentence adds essential information without redundancy or waste.

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?

Despite no output schema, the description explains the return format and parameter usage. It covers all necessary aspects (file locations, filtering, ordering) for an agent to successfully invoke the tool. The context signals (4 params, none required) are well addressed.

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 baseline is 3. The description adds value by explaining how to combine parameters (e.g., 'Combine session, last, and entry_type to narrow the result') and providing context on file paths, which exceeds mere schema documentation.

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 identifies the action ('Read recent entries') and the resource ('consumer project's chat-history JSONL'), including specific file paths. It distinguishes itself from sibling tools like chat_history_append (write) and memory_lookup (different resource).

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 states when to use the tool: 'Use to recover context from an earlier session — decisions, notes, phase markers — at the start of a new task.' It provides clear context but does not explicitly exclude alternative use cases or list alternatives, which are minimal among siblings.

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