compare_sessions

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

With no annotations, the description carries the full burden. It discloses the return format and gives a sense of being a non-destructive comparison, but does not explicitly state read-only behavior, error cases, or system requirements.

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 well-structured with Purpose, Use case, Args, Returns, and Examples. Each section earns its place and is efficiently written, with examples illustrating usage.

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 output schema exists, return values are covered. The description includes inputs, outputs, usage context, and examples. Missing edge behaviors such as error handling or local vs remote session handling, but overall robust.

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 compensates by providing an Args section: 'session_a_id: First session ID', 'session_b_id: Second session ID', 'project_root: Optional project root for local sessions'. This adds meaning beyond the bare schema, though not highly detailed.

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: 'Compare two sessions and return differences' with a specific verb and resource. It distinguishes from siblings like merge_sessions by focusing on comparison, not merging.

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?

Provides clear context: 'Useful for understanding what decisions and patterns differ between two developer sessions or team branches before merging.' This implies usage timing and purpose, though it does not explicitly name or exclude alternative tools.

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