Start Tool Session

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

Annotations are mostly neutral (no contradictory hints). The description adds the context of 'short-lived' and 'allowlist,' which goes beyond the schema but does not fully disclose behavioral traits like what happens upon session expiry or whether any side effects persist. With annotations covering the basics, the description provides marginal extra 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 long, front-loads the core purpose, and contains no redundant or extraneous information. Every word earns its place, achieving maximum efficiency.

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 description adequately covers the essential idea of session creation for tool scoping, given that it has an output schema and minimal sibling context. However, it could be more complete by mentioning the relationship with 'end_tool_session' or the default TTL. Slight room for improvement.

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 parameters are already documented in the input schema. The description does not add any additional meaning or constraints beyond what the schema provides (e.g., it does not clarify expected values for 'tools' beyond 'registered tool names'). The baseline score of 3 is appropriate.

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 purpose: 'Create a short-lived allowlist for discover_tools and run_tool.' It identifies the specific verb ('Create'), resource ('allowlist'), and scope ('for discover_tools and run_tool'), effectively distinguishing this session-management tool from siblings like 'end_tool_session' and 'tool_session_status'.

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 advises to 'Use this to keep a task scoped to the tools it actually needs,' providing clear context for when to invoke the tool. However, it does not explicitly mention when not to use it or list alternatives, such as skipping session creation for tools that don't require it. The guidance is adequate but lacks exclusionary detail.

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