session_add_variable

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

With no annotations, the description carries full burden for behavioral disclosure. It mentions supported types and the bits parameter, but fails to disclose side effects (e.g., variable persistence, duplicate handling), error conditions (e.g., invalid session), or the fact that session_id defaults to 'default'. This is insufficient transparency.

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 two sentences, front-loaded with the primary action, and every word is necessary. There is no redundancy or verbose phrasing.

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 tool's role in a solver session and the presence of sibling tools like session_push/pop and session_add_constraint, the description lacks context about session lifecycle, variable uniqueness, or order of operations. No output schema is provided, so the description should at least hint at return values or state changes, which it does not.

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 coverage is 100%, so the baseline is 3. The description adds that bits is only relevant for bitvec, which is already implied by the schema. It does not provide additional meaning beyond what the schema offers, so no bonus.

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 verb 'Add' and the resource 'variable to the current solver session', which distinguishes it from sibling tools like session_add_constraint that add constraints. The supported types are listed, providing a specific and immediately usable purpose.

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 that this tool is used to add variables to a session, but it does not provide explicit guidance on when to use it versus alternatives (e.g., before adding constraints) or any prerequisites (e.g., session must exist). No when-not-to-use scenarios are mentioned.

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