session_diff

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

With no annotations, the description bears the full burden of behavioral disclosure. It does reveal the nature of outputs (tool usage differences, call counts, similarity %), implying a read-only comparison. However, it omits details like error behavior when sessions are invalid, how sessions are identified, or any side effects. It is minimally transparent but not misleading.

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 a single, focused sentence that leads with the action and resource, then lists specific outputs in a compact list. Every word contributes information, with no filler or repetition.

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?

The tool has no output schema and no annotations, so the description must provide enough context for an agent to invoke it correctly. It lists the types of comparisons performed, which is helpful. However, it does not explain the return format, how similarity is calculated, whether session IDs must be from existing sessions, or what happens if sessions are missing. Given the tool's simplicity, the coverage is adequate but not thorough.

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 must compensate by explaining the parameters. It only vaguely refers to 'two sessions' without mapping to session_id_a and session_id_b, nor does it indicate where to get these IDs or their format. The schema itself is simple (two integers), but the description adds no value in parameter understanding.

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 uses a specific verb ('Compare') and a clear resource ('two sessions'), and enumerates exactly what the comparison yields: which tools were used in one session but not the other, call count differences, and similarity percentage. This distinguishes it from all sibling session_* tools, making its purpose unmistakable.

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 implies a clear context: use this when you need to diff two sessions. No explicit alternatives are mentioned, but none of the sibling session tools perform comparison, so the usage context is clear. It lacks explicit 'when not to use' guidance, but the intended scenario is obvious.

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