list_agent_sessions

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

Annotations already declare readOnlyHint=true, and the description adds a meaningful behavioral nuance: provider failures are returned separately from an empty session list rather than failing the whole operation. This helps an agent interpret partial results, though it does not describe pagination or session fields.

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 short sentences, front-loaded with the action and scope, followed by a useful failure-mode detail. There is no filler or redundant restating of the tool name.

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 low-complexity read-only listing tool with one optional enum parameter and no output schema, the description covers the most important behavior: sessions are discovered across providers, and provider failures are handled separately. It leaves out exact return fields and provider configuration details, but provides enough for correct invocation.

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%, yet the description never explains the optional provider parameter or whether it filters to one provider. The phrase 'across configured providers' weakly implies the default scope, but the agent is left to infer how the enum values behave.

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 states a specific verb ('Discover') and a specific resource ('native sessions across configured providers'), which makes the tool's function clear. It is distinguishable from sibling list tools like list_agents and list_threads, though it does not explicitly contrast itself with them.

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 usage: use this when you need to discover native sessions across providers. However, it provides no explicit when-to-use or when-not-to-use guidance, nor does it name alternatives such as session_create or session_resume for working with sessions.

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