count_schemas

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

With no annotations provided, the description carries full burden but offers minimal behavioral insight. It doesn't disclose whether this is a read-only operation, what permissions are required, whether it counts active vs all schemas, or how results are returned (e.g., as a number, with metadata). The phrase 'Count the number' implies a simple read operation but lacks critical details for safe invocation.

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 a single, efficient sentence that front-loads the core purpose without unnecessary words. Every part of the sentence ('Count the number of schemas in a context or registry') contributes directly to understanding the tool's function, making it optimally concise for its limited content.

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?

Given the tool's moderate complexity (2 parameters with no schema descriptions, no annotations, no output schema), the description is incomplete. It doesn't explain parameter usage, behavioral constraints, or return format, leaving significant gaps for the agent to guess. For a counting tool with undefined parameters, more context is needed to ensure 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?

The input schema has 0% description coverage, so the description must compensate but fails to do so. It mentions 'context or registry' but doesn't explain what these parameters represent, their format, whether both can be used simultaneously, or what happens when neither is provided (since both default to null). The description adds minimal value beyond what's inferred from parameter names.

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 clearly states the action ('Count') and resource ('number of schemas'), specifying the scope ('in a context or registry'). It distinguishes from obvious siblings like 'count_contexts' and 'count_schema_versions' by focusing on schemas, though it doesn't explicitly differentiate from tools like 'list_subjects' or 'get_schema_versions' that might also involve schema enumeration.

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 provides no guidance on when to use this tool versus alternatives. It doesn't mention prerequisites, when to choose 'context' vs 'registry' parameters, or how it differs from sibling tools like 'list_subjects' or 'get_schema_versions' that might provide similar counting functionality. The agent must infer usage from the tool name alone.

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