Plans — Get

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

Annotations already cover the safety profile (readOnlyHint=true, destructiveHint=false, openWorldHint=false), so the description is free to add the delta-sync behavior — a genuinely useful trait not derivable from structured fields. It stops short of error behavior or what 'full data' resolves to when plan_id is null.

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 tight sentences, front-loaded with the [READ] tag and the core action, then the optional delta-sync mechanism. Every sentence earns its place and none repeats the schema.

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?

An output schema exists, so return values need not be spelled out, and the delta-sync loop is fully explained. The remaining gap is the null/omitted plan_id case, which is left undefined for a tool where that parameter is not required.

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 0%, so the description carries the burden. It explains last_knowledge_of_server well (delta sync semantics and the server_knowledge handshake), but says nothing about plan_id, which is optional with a null default — an agent cannot tell what omitting it does.

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 and resource ('Get a single plan') plus the scope of returned data ('full account, category, and month data'), which implicitly separates it from plans_list. It never names plans_list or plans_get_settings explicitly, so sibling differentiation is inferred rather than stated.

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?

It gives one concrete usage condition: pass last_knowledge_of_server for delta sync. But it never says when to prefer this tool over plans_list or plans_get_settings, nor when plan_id should be omitted (its default is null). Usage context is implied but incomplete.

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