session_start

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

Beyond the annotations, the description discloses the return format (MUST/REF instructions), the overflow-summarization behavior, the non-MCP skip path, side effects of compliance tracking (recording and returning inject_session_id), and the authentication requirement. These are substantive behavioral details that an agent would not know from the annotations alone.

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 dense but front-loaded: the core purpose and return behavior come first, followed by special cases and side effects. Four sentences are appropriate for the complexity, though a slightly tighter wording could have preserved the same information with less reading overhead.

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?

With no output schema, the description carries the full burden and does so completely: it explains the return format, the overflow fallback, the non-MCP skip path, compliance tracking side effects, and authentication requirements. An agent has everything needed to invoke and interpret the result correctly.

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 100%, so the schema already documents each parameter's meaning. The description adds marginal context by noting that memories are filtered by agent identity and that api_key is for authentication, but it does not meaningfully enrich the semantics of project, agent_type, or context_hint beyond what the schema provides.

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 opens with a specific verb and resource ('Start an agent session') and immediately explains what it returns: relevant memories filtered by agent identity, formatted as MUST/REF instructions. It clearly distinguishes this session-initialization role from retrieval siblings like search_memory, which is named as the fallback for overflow details.

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 makes the usage context explicit: it is the session-start step that primes the conversation with injected memories, and it names search_memory for overflow details and report_compliance for later compliance reporting. It does not state explicit exclusions (e.g., when not to call it), but the context is clear enough for an agent to select it correctly.

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