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

Annotations already declare readOnlyHint=true and destructiveHint=false, so the safety profile is covered. The description adds valuable context beyond annotations: it clarifies that the session key is a reference, not an authentication credential or secret, which helps prevent misuse. It also preps the agent for what the return value includes. Slight gap: doesn't mention pagination or limit behavior, but that's not critical for a list tool.

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?

Three sentences: first states purpose, second explains output and usage, third clarifies the nature of the session key. No fluff, information is front-loaded, and each sentence adds distinct value. Well-structured for an AI agent to parse quickly.

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?

For a simple listing tool with one well-described parameter and strong annotations, the description is complete. It explains what the tool returns, how to use the returned data, and the nature of the key identifier. The output schema is present, so the description doesn't need to enumerate return fields. It also references sibling tools appropriately, giving full context for the agent's decision-making.

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?

The schema has a single required parameter (project_id) with a description 'the project.' Schema coverage is 100%, so the baseline is 3. The description adds minimal extra meaning about the parameter, only implying it's tied to 'a project's sessions.' Since project_id is self-explanatory and no other parameters exist, the schema carries the semantic load adequately.

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?

Description starts with a clear verb ('List') and resource ('a project's development sessions'), clarifies they are conversation threads, and distinguishes from siblings by explicitly mentioning how the result feeds into other tools (dreamagent_chat, dreamagent_get_chat_status). This goes beyond a generic list operation and makes the tool's role unambiguous.

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?

Explicitly explains when to use this tool: to select, continue, or monitor a session. It names the exact alternate tools for each follow-up action (dreamagent_chat to continue, dreamagent_get_chat_status to monitor), giving the agent clear context on when this tool is the right choice versus its siblings.

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