session_get

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

With no annotations, the description carries the full behavioral burden and discloses that it is a read-only filesystem read, has no side effects, requires a previously saved session file, and falls back to the previous session when today's brief is unavailable. It does not cover authentication, rate limits, or exact return structure, but it is substantially transparent for a read-only retrieval 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?

The description is compact and front-loaded with the core action, followed by return behavior, usage guidance, side effects, and limitations. Every sentence adds useful information without redundancy.

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 one-parameter read tool with no output schema, the description explains what is returned and under what fallback condition. It could clarify how the optional date parameter interacts with the fallback behavior, but it is otherwise sufficient 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 100%, and the single date parameter is fully documented as YYYY-MM-DD with a default of today. The description adds no additional parameter meaning beyond what the schema already provides, so the baseline score of 3 applies.

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?

States a specific verb and resource: retrieve archived session briefing from local session history. It also clarifies the fallback return behavior. Sibling differentiation is limited because it does not explicitly compare itself to morning_brief or session_save, but the core purpose is clear.

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?

Provides explicit WHEN TO USE guidance: reviewing past daily biases or comparing today's price action against previous morning briefings. It does not list when not to use the tool or name alternative siblings, so it stops short of a full routing instruction.

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