session_update

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

There are no annotations, so the description carries the full behavioral disclosure burden. It states that information is added to a session but does not disclose side effects, whether a session must already exist, whether entries are append-only, or what happens on repeated calls. This is only slightly more informative than the tool name itself.

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?

Two sentences with no filler. The main action is front-loaded, and the list of supported record types is compact yet informative. Every clause earns its place.

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 10 parameters, no output schema, and no annotations, the description should provide more guidance about preconditions, session lifecycle, and how this tool relates to session_init, session_checkpoint, and session_log. The description explains high-level intent but leaves an agent uncertain about operational details.

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 high at 80%, so most parameter meaning is already available. The description adds value by naming the kinds of information that map to the 'type' enum, but it does not explain nuanced parameters like reasoning, risk_level, or context_pct beyond what the schema already says.

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 identifies a specific action ('Add information') on a specific resource ('current session') and lists the categories of information it records. Clear enough for an agent to understand the core purpose, though it does not explicitly differentiate itself from siblings like session_log.

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 gives clear timing guidance ('Use this throughout the session') and enumerates valid content types. It does not state when not to use this tool or contrast with alternatives such as session_checkpoint or session_log, which keeps it from a 5.

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